Many heavy duty vehicles such as dump trucks and tractors for eighteen (18) wheelers have a Hendrickson "Walking Beam" suspension which is disposed generally longitudinally and is arranged on each side of the vehicle. The Hendrickson suspension is a major support system for heavy duty vehicles, and the suspension moves very slightly in all three directions to absorb shock and stress on the vehicle. Hence, the suspension is called a "Walking Beam".
This Hendrickson "Walking Beam" suspension has a stack of leaf springs disposed above the beam, and the beam has an enlarged center portion provided with a bronze bushing therein. This bushing is lubricated by means of a grease fitting threaded into the beam near the center thereof.
Unfortunately, this grease fitting is located on the inner side of the Hendrickson suspension and is not accessible from the outer side of the vehicle. In order to lubricate the "Walking Beam" suspension (and more particularly, the grease fitting thereon), a truck driver, mechanic or maintenance person must lie down under the vehicle and face upwardly so as to bring a grease "gun" or applicator to the fitting. Usually, the person lies on a "creeper" and slides under the vehicle. Also, the vehicle may be in a field situation, and not in a garage, whereby access to the underside of the vehicle is even more difficult. The person lubricating the "Walking Beam" suspension must assure that the vehicle is not driven or moved while he (or she) is under the vehicle. There is a possibility of injury and, as a result, a reluctance to lubricate the suspension. Consequently, the vehicle suspensions are not lubricated on a weekly basis as recommended, and the lack of proper lubrication detracts from the life and reliability of the "Walking Beam" suspension and precipitates early failure and costly repairs and replacement (as well as "down time" for the heavy-duty vehicle).
Despite the existence of this problem for many years, and despite the great body of prior art on lubrications (generally) no one, to date, has solved this inherent problem nor facilitated a convenient means for lubricating the "Walking Beam" suspension.
For example, Hirst, in U.S. Pat. No. 1,447,177, disclosed a leaf-spring-lubricating device, wherein a lubricant-conveying pipe is screwed into one side of a receptacle and is bent to extend vertically. The lubricant passes from the receptacle down through bolt holes and is distributed between and along the individual spring leaves.
Van Pelt, in U.S. Pat. No. 1,580,181, disclosed a lubricator, wherein a transverse suspension bar is attached at its ends to the vehicle frame. The supply of oil is fed to the lubricating pad through an oil feed pipe or tube preferably fashioned integrally with the attaching plate and extending along one side thereof from the holder with which the pipe communicates.
In U.S. Pat. No. 2,003,032, Barks et al disclosed a lubricating apparatus, wherein oil passes through a member and out of a nozzle to a position from whence it spreads within the confines of canvas surrounded by a metallic cover. A C-shaped clamp is provided having an adjustable buttress screw and an oppositely located clamp screw, the latter being hollow and containing a slidable inlet tube. The inlet end of member is provided with a suitable connection for a lead-in hose, the other end of which is connected to a suitable lubricant compressor.
A curved tube for a grease gun was disclosed by House in U.S. Pat. No. 2,614,660.
Jones, Jr., in U.S. Pat. No. 3,743,054 disclosed a means for a trailer fifth-wheel lubrication, wherein a lubricating tube is welded or otherwise secured to the bottom plate of a tractor and is disposed parallel with the longitudinal axis of the trailer. The projecting front end of tube is connected to a grease gun adapted to be manually manipulated. Grease from the cartridge within the gun is forced through a tube and deposited through openings in the tube through registering holes in the plate.
In U.S. Pat. No. 5,339,924, Martins discloses a dosing device for a lubricating mechanism. A housing with a defined volume has a piston movable in an axial direction to define two chambers. The chambers are connected to a supply of lubricant. The applicant is also aware of a manifold type of lubricating system used on earth-moving and excavating types of heavy equipment. In this manifold system, a single fitting into which lubricant is introduced, is connected to a plurality of hoses or tubes which direct the lubricant to the parts of the equipment which require lubrication. This lubrication system is factory installed and the applicant is not aware of any retrofit devices which are available.
However, none of these prior art devices are directed to nor readily applicable to, a Hendrickson "Walking Beam" suspension, nor are these prior art devices directed to an adapter to retrofit a vehicle to facilitate lubrication from a side of the vehicle, thereby avoiding the need to lubricate from beneath the vehicle.
The applicant is also aware of a lubrication system used on heavy duty equipment such as cranes made by the Catapiller Corp. The lubrication system has a single fitting which is connected to a manifold to direct the lubricant to a plurality of bushings and joints which require lubrication. The manifold system is distinguishable from the present invention in that it is a manifold, is not retrofit but is original equipment, and is not mounted on a Hendrickson or similar suspension.